Glass fiber sizing composition



' u 9, 1966 TRIPLE-new. 3,265,516

GLASS FIBER SIZING COMPOSITION Filed April 18, 1962' 2 Sheets-$heet 1 SIZING COMPOSITION HYDROXYALKYLATED HIGH-AMYLOSE STARCH ADDITIONAL FILM FORMER SELECTED FROM GROUP: UNMODIFIED smacu 2. CROSS LINKED STARCH a. ACID TREATED, HYDROLYZED $TARCH,HAVING A FLUIDITY OF ABOUT 30 TO 50 '4. POLYMER or OLEFIN CONTAINING 2 re; s CARBON AroMs-MoLecuLAR weusm or 1400 re 2500 LUBRICANT TEXTILE sarremsa WATER BYMMIIPE mmunm' M Aug. 9, 1966 T l TT ETAL 3,265,516

* GLASS FIBER SIZING COMPOSITION Filed April 18. 1962 z Shets-Sheet 2 6000 YARDS FROM OUTSIDE OF FORMING PACKAGE STARCH Sl'LE OF THE INVENTION U r! m 5 9f 2 .J 6 4 2 Q Q 5 l 8 O O 8 fi a o m (5 m o m d a a INVENTORS SSO! NOLLIN I 1; z. m/nsrr United States Patent 3,265,516 GLASS FIBER SIZING COMPOSITION Benny L. Triplett, Shelby, N.C., and James J. Fasnacht,

Donald E. McWilliams, and George E. Eilerman, Pittsburgh, Pa., assignors to Pittsburgh Plate Glass Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Apr. 18, 1962, Ser. No. 188,359 14 Claims. (Cl. 106-213) This invention is directed to a process for preparing glass fibers, and it has particular relation to the application of a size to continuous filament glass fiber strand during the formation of the strand.

In the production of continuous filament glass fiber strands, a number of individual glass filaments are drawn from an electrically heated, platinum alloy bushing containing a molten supply of the glass. The glass passes through tips which define orifices in the bottom of the bushing and form inverted cones of glass at the ends of the tips. Individual filaments are drawn from the cones of glass at a high rate of speed, i.e., 5,000 to 20,000 feet per minute, and are grouped into a strand as they pass over -a suitable guide. The strand is thereafter wound on a rapidly rotating forming tube.

There is no twist in the strand as it is thus formed, and an aqueous size composed of an aqueous dispersion of a binder and a lubricant, such as dextrinized corn starch and a vegetable oil, is applied to the individual filaments prior to the time they are grouped into the strand and wound on the tube in order to bond them together and maintain the integrity of the strand. The strand is wound on the tube with a slight traverse so that succeeding turns cr-oss each other at an angle rather than being parallel to each other so that the strand can be more easily removed from the tube.

One problem which occurs in the manufacture of continuous filament strand in this manner is that of size migration. Size migration is a phenomenon which occurs in the strand after it is wound on the forming tube. As stated above, the size is an aqueous dispersion of ,dextrinized corn starch and vegetable oil. The solids content of the conventional dextrinized starch-oil size is about 12 percent by weight with the remainder being water. Some of this water must be removed from the strand before it is twisted to form yarn. This water is removed from the strand by drying the strand which is Wound upon the forming tube. As the strand forming package dries on the forming tube, the water moves from the inside of the forming package next to the tube to the outside of the forming package. This movement of the water carries with it some of the starch and oil of the size so that the strand in the outside layers of the package has a much higher size solids content than the strand in the layers beneath the surface.

Size migration creates a number of problems in subsequent fabrication of the strand. warping, quilling and weaving of glass fiber yarn there are a number of winding and unwinding operations where the tension exerted on the yarn is important. The tension exerted on the yarn during these operations must be relatively constant. If the tension on the yarn is uneven during these operations, the individual filaments making up the yarn are likely to be broken and produce fuzzy yarn. Fuzzy yarn clogs up the fabricating equipment and causes yarn breakout. Uneven tension on the yarn can be created by non-uniform size contents on the yarn throughout its length. Thus, it is desired that the size content on the yarn be uniform throughout its length.

Another fabricating operation where uneven size content on a yarn is troublesome is in the process of texturing yarn. Textured yarns are those continuous filament yarns which have been bulked by an air jet, such as de- In twisting, plying,

scribed in U.S. Patent No. 2,783,609. The size content of the yarn which is textured determines the resistance of the yarn to being textured or bulked by the air jet. A variation in size content along the length of the yarn results in a variation in the degree of bulking. Any variation in the degree of bulking of the yarn shows up in the fabric and may be serious enough to result in rejection of the piece of goods.

An additional problem due to size migration is encountered when woven fabrics are heat treated. The strand with the higher size-solids content shows up differently from the strand with the lower size-solids content when the twisted strand is woven into a fabric, and the fabric is heated to remove the size and set the fibers in the fabric. This heating is conducted at a temperature of about 1200 to 1400 F. for 8 to 15 seconds, and is sufiicient to volatilize the solids and remove them from the fabric, and to soften the glass fibers in the glass fabric to set them in their new position. This process is de scribed in greater detail in U.S. Patent No. 2,845,364.

After the heat treatment, the strand from the outside of the forming package which strand originally had the higher size-solids content shows up as a filling band in the fabric which reflects light to an extent dilferent from the rest of the fabric. Sometimes this band exhibits a moire effect. This results in an imperfection in the fabric which is of suflicient magnitude to cause rejection of the fabric.

It is not known exactly what causes the difierence in appearance in the yarn in the fabric; however, it is believed that it may be due to incomplete removal of the size, or it may be due to a difference in the orientation of the individual filaments in the yarn due to the increased heating activity which occurs in the areas of increased size solids content when the fabric has been sufficiently heated to remove all of the size throughout the fabric. In any event, this difference has definitely been noted, and has been a cause for serious concern with the yarn manufacturers and weavers. The above defects have also occurred in fabrics woven with textured, continuous filament glass yarns.

As can be surmised from the description above concerning the defects in woven fabrics caused by size migration, this problem has been a most serious problem and has required drastic steps to overcome it. These steps have involved the stripping or running olf of the strand on the outside of the forming package to remove that portion of the forming package which contains strands having a higher size content than the remainder of the package. This represents a substantial loss in the production of strand, and also requires a costly and undesirable intermediate step between the forming and twisting of the strand.

Apart from the problems which are caused by size migration, conventional starch-oil sizes have been difficult to texturize by the air jet process mentioned above. The starch binder has been observed to flake and be blown off of the yarn being subjected to the jet. This creates an atmosphere problem which is annoying to the operators. It also clogs the texturing jet, and results in uneven texturing of the yarn. Deposits of starch build up in the jet, and reduce the texturing effect as they are built up. The back pressure in the jet then builds up until finally the pressure is sufficient to blow out all of the starch accumulation at once, and the complete texturing effect is again resumed. This results in a chattering effect in the jet and uneven texturing of the yarn passing through the jet.

Another problem generally present when sizing glass fibers with starch sizes is that of shedding, also known as powdering. Shedding is the removal of small pieces of binder size which is caused by a peeling of the size from the glass fibers as the sized glass fibers (e.g., sized glass fiber yarn) pass over some contact surface or point during a fabrication step, e.g., when sized strands are being warped. Shedding leaves an accumulation of powdery size on fabricating equipment, mostly on those parts of the equipment which contact the sized fibers.

The starch sizing composition of this invention has excellent shedding proporties in that very little shedding occurs during fabrication steps, such as twisting, plying, warping, weaving, etc.

Moreover, the starch sizing compositions of the instant invention demonstrate excellent runability and good wet out properties with almost complete freedom from binder throw-01f and strand break outs (breaking of filaments) during strand forming and sizing operations.

It is, therefore, an object of this invention to provide an aqueous size which can be easily applied to glass fiber strand during its formation in uniform, controlled amounts and whose non-aqueous constituents will not migrate in the strand forming package upon drying of the package on the forming tube.

4 It is a further object of this invention to provide such a size which will permit the strand to be twisted, uniformly textured if desired, quilled or warped, and woven into cloth With uniform tension and with a minimum of broken filaments in these various fabricating operations.

It is also an object of the invention to provide an aqueous size whose solids constituents can be readily and completely removed from a woven fabric by the conventional heat treatments which are applied to fabrics to remove the size ingredients and set the fibers in the article.

The objects of the invention are achieved by application to a strand during its formation of an aqueous size containing as the binder ingredient a high amylose containing starch of the formula X-OY wherein X is a starch having an amylose content of from about 50 percent to 100 percent by weight;

O is an oxygen atom from a hydroxyl group in the amylose portion of the starch molecule; and

is a hydroxy alkyl radical having from 2 to 3 carbon atoms,'and wherein Y is a substituent on the amylose portion of the said starch with I3. weight average frequency of occurrence of from about 0.1 to about 30 Y substituents, and preferably about to 20 Y substituents, per 100 d-glucopyranose units of the amylose portion of the starch.

Thus, the above formula includes not only high amylose content starches having homogeneous (regular) hydroxyalkylsubstitution, viz., where each group of 100 d-glucopyranose units has from 1 to 30 Y substituents, but also 4 is 1 Y substituent per 100 d-gluoopyranose units. If the entire amylose polymer has an equivalent pattern of substitution, then the weight average frequency of occurrence of Y substituents per 100 d-glucopyranose units of the amylose polymer would be 1.0.

The size also contains other ingredients, such as a vegetable oil as a lubricant, a bactericide such as formaldehyde, a softening agent and a wetting agent. Small amounts of additional film forming agents, other than the previously mentioned amylose containing starch of the above-said formula, can also be included, such as for example: other starches; modified starches or starch derivatives; aqueous emulsions of readily emulsifiable low molecular weight linear polyolefins, e.g., polyethylene and polypropylene having a low molecular weight of about 1400 to 2500; etc. These 'adjuvant film forming materials are sold by Eastman Chemicals under the trade name Epilene, and can be employed to make a more durable strand.

The basic amylose containing starch, from which the derivatives of the above formula are secured, can be derived from any sources including high amylose containing starch hybrids of corn, wheat, potato, tapioca, sago, or rice. Of course, thehigh amylose containing starch can also be derived through fractionation of the starch content of ordinary corn, Wheat, potato, tapioca, sago, or rice to obtain a high amylose content fraction. As used hereinafter in the specification and claims, the expression high amylose containing starch means a hybrid starch or fraction of a naturally occurring or synthesized starch containing from about 50 to 100 percent by weight of amylose (with the remaining 0 to 50 percent being amylopectin or a derivative thereof).

The hydroxyalkyl derivatives of the aforesaid high amylose containing starches can readily be prepared by reacting a lower alkylene oxide, e.g., ethylene oxide or propylene oxide, with any of the aforesaid high amylose containing hybrids or high a r n ylose containing fractions of naturally occurring or synthesized starches. Thus, hydroxyalkyl derivatives can be prepared by reacting a high amylose containing potato starch with ethylene oxide to prepare a high amylose containing starch having hydroxy lower alkyl, in this case hydroxyethyl, substituents on the reoccurring d-glucopyranose units of the amylose polymer.

While in the above formula, XO-Y, the high amylose starch has been shown as X, it will be realized that this has been done for purposes of simplifying the discussion in conjunction therewith. Actually amylose, such as obtained from potato starch, is conventionally thought to be a linear polymer containing successively linked C H O (d-glucopyranose) units according to the formula:

heterogeneous (irregular) hydroxyalkyl substitution, viz., where any given group of 100 d-glucopyranose units can have zero (no) Y substituents but other groups of 100 d-glucopyranose units have sufficient Y substituents to satisfy the limitation of from 0.1 to 30 Y substituents per 100 d-glucopyranose units based on the total amylose polymer. For example, if one group of 100 d-glucopyranose units has no Y substituents and an adjacent group of 100 d-glucopyranose units has 2 Y substituents, then the weight average frequency of occurrence of Y where N is the number of reoccurring C H O units in the polymer. As is apparent from this formula, the C H O (d-glucopyranose) units are joined by 1,4 alpha linkages. The molecular weight of amylose varies from about 100,000 to about 200,000 as calculated from intrinsic viscosity measurementsin l N potassium hydroxide according to the method outlined by Potter and Hassid in 70 J.A.C.S. 3774-77.

' For convenience sake, X in the formula, X-OY, designates the amylose polymer of the high amylose conunits for those two groups of 100 d-glucopyranose units taining starch., Thus, it is clear that the hydroxyalkyl substituent Y can be present many times on the amylose polymer backbone. Each monomeric C H O (dglucopyranose) unit has three hydroxyl groups available for reaction with the lower alkylene oxide, and the lower alkylene oxide can react with any one(s) or all of them.

Instead of reacting the lower alkylene oxide with a high amylose containing fraction or hybrid of starch, the lower alkylene oxide can be reacted with substantially pure amylose, such as an amylose starch having an amylose content of about 80 to 100 percent by weight. The use of a substantially pure high amylose starch wherein the Y substituents are hydroxyethyl is most preferred according to this invention. Hydroxyethy-l lamylose starches having an amylose content of from about 50 to 100 percent by weight, and more preferably from 80 to 100 percent by weight, are the preferred high amylose containing starch derivatives employed in accordance with this invention.

These hydroxyalkyl amylose starches coming within the formula, X-O-Y, as defined hereinabove, are water soluble, or water dispersible depending upon the degree of hydroxyalkyl substitution, with the higher substituted amylose products giving the greater water solubility.

As an exemplary commercially readily available hydroxyalkyl starch derivative coming within the abovementioned formula, Hydroxyethyl Superlose can be mentioned. Hydroxyethyl Superlose is essentially hydroxyethyl amylose formed by reacting essentially pure amylose (derived by fractionation of potato starch) with ethylene oxide. The fractionation procedure can be conducted conveniently according to US. Patent Nos. 2,829,- 987; 2,829,988; 2,829,989; and 2,829,990.

Another exemplary hydroxyalkyl starch derivative is the ethylene oxide reaction product with Amylomaize. Amylomaize is a hybrid corn starch having approximately 55 percent by Weight amylose.

Hydroxyethyl Superlose and Amylomaize are both products of Stein Hall and Company, Inc., New York, New York. These starches, when formulated into aqueous systems with the addition of other adjuvants, such as lubricants, bactericides, and various softening and conditioning agents, are eminently suitable as aqueous sizing compositions for application to glass fiber strands during their formation to impart non-migratory characteristics and superior abrasion resistance thereto. It is also observed that by the application of aqueous sizing compositions containing amylose starch derivatives of the aforesaid formula, the problems of shedding, break out and binder throw off are substantially eliminated. Moreover, the instant invention allows the uniform application of the aqueous sizing composition with good runability throughout the sizing process, viz., the sizing composition can be applied to the glass fibers easily without clogging the apparatus.

In addition, due to its non-migratory characteristics, the said sizing composition can be easily and uniformly removed from the glass fibers (after the fabrication has been completed, e.g., after the strands have been woven into fabric) during the burn-off procedure without leaving unsightly grey bands which cause variance in the light reflecting properties of woven glass fabric. Thus, by use of the present invention, rejects can be substantially reduced by avoiding the aforementioned defects of nonuniform size application, size migration, variance in light reflectance, etc.

As previously mentioned, the average frequency of occurrence of the Y substituents per 100 d-glucopyranose units of the high amylose containing starch is from about 0.1 to about 30.0 Y substituents per 100 d-glucopyranose units. Preferably, however, the frequency of the Y substit-uents is from about to about 20 Y substituents per 100 d-glucopyranose units. Any amylose fraction of a starch can be employed in accordance with this invention as long as the said fraction contains from about 50 to about 100 percent by weight of amylose.

Preparation of aqueous size compositions The aqueous size compositions suitable for use as non migratory, abrasion resistant starch sizes for glass fiber strands in accordance with this invention are conveniently prepared in the following manner: The amylose containing starch of the formula, XO-Y, is mixed with a lubricant, such as a water-soluble mixture of'ethylene oxide and propylene oxide, 21 surface active wetting agent, such as an ethylene oxide derivative of a sorbitol ester, and a textile softener, such as 'an alkyl 'imidazoline reaction product of tetraethylene pentamine and stearic acid. A bactericide, such as formaldehyde, is usually added in sufficient amounts to prevent mold attack on the said high amylose containing starch derivative.

A sizing composition is conveniently prepared by first adding about half the total amount of water to a mixing kettle. Suitable amounts of high amylose containing starch derivative of the formula, XOY, as defined above, are then added to the water to form a slurry. The pH of the slurry is about 4.5. This slurry is heated (cooked) at a sufficient temperature and for a sufficient length of time to allow the said high amylose containing starch derivative to go into aqueous solution. A processing oil, such as a hydrogenated vegetable oil, is then added to the batch. The said oil is generally a solid material having the consistency of lard, and it is first melted and then emulsified with water, the wetting agent, and a small amount of the aqueous high amylose containing starch derivative solution before it is added to the main portion of the aqueous size. The textile softener, dispersed in water, is next added to the sizing batch, and the bactericide is thereafter added.

The aqueous sizing composition, as thus prepared has a pH of about 5.0 to 5.4. The sizing solution is adjusted to or maintained on the acid side to facilitate better solubility of the soluble constituents of the size. The aqueous sizing composition has a viscosity of about 1 to 100, and preferably about 1 to 20 centipoises at 20 C. using a Brookfield viscometer (Model No. LVP with spindle size No. 1 rotating at 30 revolutions per minute), and a high amylose containing starch derivative content of about 2 to 4 weight percent. If the aqueous sizing composition contains the high amylose containing starch derivative in a weight percent substantially in excess of 4, then the outer layers of the sized strands on the forming package are bonded too tightly to permit removal thereof without filament breakage.

The ability of the aqueous sizing composition of this invention to be picked up by the glass strands is enhanced by including in the aqueous sizing composition other starch materials, such as unmodified corn starch, as adjuvant film forming materials. A lesser or greater proportion of the unmodified adjuvant starch material can be employed as compared to the amount of high amylose containing starch derivative. In place of or in addition to unmodified corn starches, other adjuvant starch materials can be employed in conjunction with the high amylose containing starch derivative in accordance with the present invention. Such starch materials as cross-linked starches, e.g., starches cross-linked with phosphorus oxychloride as described in US. Patent No. 2,328,537, or with epichlorohydrin can be used. Acid treated corn starches, e.g., corn starches prepared by hydrolyzing corn starch with sulfuric acid to correspond to a fluidity of about 30 to 50 and preferably a fluidity of about 40. The term fluidity as used herein is indicative of the number of cubic centimeters of an aqueous alkaline starch solution which runs from a funnel in seconds at 25 C. The term fluidity is defined more fully in Chemistry and Industry of Starch, second edition (1950) by Ralph W. Kerr, at pages 133-134, Academic Press, Inc.

Emulsions of low molecular weight polyolefins, e.g., polyethylene and polypropylene, can also be used as adjuvant film forming materials to make a more durable strand.

In cases where either cross-linked starches or acidhydrolyzed starches or both are employed in conjunction with the high amylose containing starch derivatives, it is preferable to conduct a preliminary cooking operation for the individual adjuvant starch(es) in question, e.g., by cooking the starch(es) with water at sufiicient temperatures and for a sufiicient period of time to gelatinize the adjuvant acid hydrolyzed starch so that it is readily miscible with water. For example, it is customary to heat the starches at the boiling temperature of the aqueous dispersion, i.e., 212 F., for about 30 minutes.

The aqueous sizing composition is applied to the glass fiber strand during forming. The sized strands are conditioned (dried at a temperature of 70 F. and 70 percent relative humidity) to reduce their moisture content prior to twisting. The amount of conditioning will depend upon the diameter and number of filaments in the strand and upon the amount of twist (turns per inch) that is to be put in the strand. In order to conditi-on these strands for twisting to impart one turn per inch in the respective strands, a 204 filament strand package is conditioned for 24 to 72 hours and a 400 filament strand package is conditioned for 8 to 20 hours. The moisture content of the strand is reduced to about 4 to 6 percent by weight preparatory to twisting.

The amount of size solids on the strand can vary from about 0.7 to about 2.0 percent and preferably from 1.0 to 1.5 percent. One of the distinct advantages attendant to this invention resides in the fact that lesser amounts of size solids can be deposited on the glass fibers to accompilish the function of a starch size binder, viz., hold the glass fibers together in strand form until the fabrication of the strands has been completed. In the case of prior art starch sizes, solid contents of from 1.7 to 2.0 percent were customarily required to insure adequate film strength and binding. However, in accordance With this invention, the same objectives can be secured with the use of solids contents of from 1.0 to 1.5 percent, thus facilitating the removal of the size solids by volatilization during the subsequent heat treatment, viz., coronization or burnolf. While solids content in excess of 1.5 percent can be used, no beneficial results are secured thereby, and this merely creates more of a problem in volatilization.

The ability of applicants invention to impart the desired binding power and fabrication properties to glass fibers while depositing fewer solids on a percentage basis is significant. This facilitates size removal because there is less size to burn off the fibers. Moreover, the coronizing equipment can handle more fabric in a given length of time, therelby permitting an increased productivity of the coronizing equipment.

Application of the aqueous sizing composition The aqueous glass fiber sizing compositions of the present invention are applied to the glass fibers during their forming While the size is at an elevated temperature, i.e., 125 to 135 F., and more preferably at a temperature of about 130 F. This is necessary in order to keep all of the ingredients of the size, especially the hydrogenated vegetable oil and the amylose containing starch derivative of the aforementioned formula, uniformly dispersed in the size. If the size is allowed to cool to, say for example, room temperature, these ingredients tend to sepa rate from the size.

The method of adding the size to the strands and analysis of the amount of size on the strand after forming and conditioning is further described in conjunction with a description of the drawings in Which:

FIGURE 1 is a diagrammatic elevation of a continuous filament, glass fiber strand operation; and

FIGURE 2 is a graph illustrating the improvement '8 of the present invention over the prior art with respect to size migration in the forming package.

In FIGURE 1 of the drawing there is shown an electrically heated, platinum alloy bushing 6 containing a supply of molten glass 7. The bushing is provided with a series of orifices in the form of tips 8 through which the glass flows and forms in small inverted cones 9 suspended from the bottoms of the tips 8. The tips are usually formed in a number of rows, for-example, 4 to 20 or more rows, having a great many tips in each row so that the total number of tips is about 200 to 400 or even more in number.

Glass filaments 10 are pulled from the cones of glass 9 at a very high rate of speed, i.e., 5,000 to 20,000 feet per minute and wound up on a rapidly rota-ting forming tube 12. The glass filaments are grouped into a strand 13 as they pass over the guide 14 prior to their being wound on the tube 12. As the strand 13 is wound on the tube 12, it is rapidly traversed by means of traverse (not shown). The size is applied by means of applicator 18 to the individual filaments in the strand prior to the time they pass over the guide. The size 20 is supplied to a reservoir 22 of applicator 18 which has a rotating roller or belt 19 mounted so as to dip into the size in the reservoir. The size is transferred from the rotating roller or belt to the filaments as the filaments pass over the surface of the wetted roller or belt. A suitable size applicator is shown in U.S. Patent No. 2,873,718.

The sizes of the present invention are easily applied to the strand during its formation, and the strand forming proceeds smoothly. After each forming package containing, for example, about 3.5 pounds of strand, is formed (204 filaments having a diameter such that there are 15,000 yards to the pound of strand), the forming tube and package are removed from the winder and the end of strand is found on the forming package. The forming package, containing about 9.5 to 10 percent by weight moisture, is then allowed to sit in an atmosphere of about 70 F. and 70 percent relative humidity for about 24 hours in order to reduce the moisture content on the strand to a range of about 4 to 6 percent by Weight. Thereafter the strand is removed from the forming package and twisted into yarn. The twisting is accomplished on conventional textile apparatus with very few broken filaments. The twisted yarn is warped or transferred onto quills for weaving, and the yarn weaves very well with very few broken filaments. The woven material can be heat treated satisfactorily.

In FIGURE 2 the graph shows a size solids content of the strand in the forming packages produced according to the present invention as compared with the prior art. The ordinate shows the percent of size solids on the strand after 21 hours conditioning at 70 percent relative humidity and 70 F. The abscissa shows the number of yards of strand as it is removed from the outside to the inside of the forming package. The dotted line represents the amount of solids of a conventional dextrinized corn starch-vegetable oil size and the solid line represents the amounts of solids of the high amylose containing starch derivative of the formula, XOY, as defined above, exhibited by the size set forth below in Example V at various points along the strand in the forming package after conditioning as described above.

It will be noted from this graph that virtually no size migration has occurred with the said high amylose containing starch derivatives, whereas considerable migration of the conventional dextrinized corn starch size occurs in the outside 4,000 yards of strand. Equivalent sizing and binding can be obtained with lower amounts of the said high amylose containing starch derivative compared to the results secured with use of the conventional starch size. The uniform amount of size solids on the strand as permitted by the high amylose containing derivative starch of the present invention provides uniform low tension in the strand during the various winding and un- 9 winding fabricating steps necessary to transform the strand into yarn and into a woven product. During these various fabricating steps, the strand (or yarn) handles well, and there are very few filaments broken during these fabricating steps. The yarn as sized according to the method as described above is exceptionally useful for bulking by means of the texturing air jet described in the above-mentioned patent. The uniformity of size content on the yarn permits uniform conditions in the texturing operation and the production of acceptable textured yarn. The size does not blow off of the yarn during the texturing as does the conventional dextrinized corn starch-oil size. =Heat treated fabrics woven from twisted strand formed in accordance with the present invention are free from the appearance defects discussed above which are due to size migration in the strand forming package.

The invention will be further illustrated by the follow ing examples in which all percentages and parts are by weight unless otherwise indicated.

EXAMPLE -I Ingredient: Amount Hydroxyethyl Superlose grams 400.0 Cation X (textile softener) do 80.0

UCON 50 HB-400 (lubricant) d 300.0 Water (sufficient to bring to a volume of 4 gallons).

Place 2 gallons of water in a mixing kettle. Add 400 grams of hydroxyethyl amylose to the water to form a slurry and then adjust the pH of the slurry to 4 to 5 with acetic acid. Cook the starch slurry for 30 minutes at 180 F. to solubilize the starch in the water. Then add 300 grams of UCON 50 HE-400 (water-soluble lubricant consisting of a copolymer of ethylene and propylene oxides and having about 50 percent ethylene oxide and 50 percent propylene oxide) to the cooked starch. Disperse 80 grams of Cation X -'(alkyl imidazoline reaction product of tetraethylene pentamine and stearic acid) in water (approximately gallon) and add the dispersion to the starch batch. Add the remaining water to bring the volume up to 4 gallons.

Apply this aqueous hydroxyethyl amylose size to glass fibers as they are being formed into strands. Condition the forming package for '6 hours at 70 F. and a relative humidity of 50 to 70 percent to reduce the moisture to about 4 to 6 percent.

Very little size migration occurred upon conditioning.

EXAMPLE II Ingredient: P Amount Hydroxyethyl amylose grams 600.0 Pureco Oil (hydrogenated cotton-seed oil) grams 410.5 Tween '81 (ethylene oxide derivative of a :sorbitol ester-wetting agent) grams 40.9 Cation X do 88.7 Formaldehyde cc 17.0 Water (suflicient to bring to a volume of 5 gallons).

Add hydroxyethyl amylose, 600 grams to 2 /2 gallons of water in a mixing kettle to form a slurry, and adjust the pH of the slurry to about 4 to 5 with acetic acid. Heat the slurry at 180 F. for 30 minutes to allow the hydroxyethyl amylose to go into aqueous solution. Add fPureco Oil, 410.5 grams, by first melting the Pureco Oil and then emulsifying it with water, Tween 81 (40.9 grams) and a small amount(200 to 400 cubic centimeters) of the aqueous hydroxyethyl amylose solution before adding to the main portion of the aqueous size.

10 Then add Cation X, 88.7 parts by weight, dispersed in about gallon of water to the sizing batch. Add formaldehyde, 17 cubic centimeters, as an optional bactericide. Adjust the pH of the aqueous sizing composition to 4 with acetic acid.

After application to glass fiber strand during formation, and drying and conditioning after formation of the strand as in Example I, very little size migration occurred. The ignition loss of size solids on the strand throughout the forming package was 09:09. percent. Strand treated with this aqueous sizing composition exhibited excellent fabrication properties when twisted and quilled, and the strand integrity was very good.

EXAMPLE III Ingredient: Amount Hydroxyethyl amylose grams 300.0 Unmodified corn starch do 700.0 Pureco Oil do 410.0 Tween 81 do 41.0 Cation X do 88.0 Formaldehyde cc.. 17.0 Water (sufiicient to bring to a volume of 5 gallons).

The procedure of Example II was repeated with the exception that unmodified corn starch, 700 grams, was included in the sizing batch by cooking 700 grams of unmodified corn starch in about -2 gallons of water for 15 minutes at F. This was then added to the previously cooked hydroxyethyl amylose solution, which had been cooked'at -190 F. for 20 minutes and then cooled to 140 F. prior to the addition of the unmodified corn starch.

The glass fiber yarn sized with this formulation had adequate binder pick-up (averaging 1.7 percent, dry basis), essentially no migration of binder, and in general good fabrication properties including excellent quilling properties.

EXAMPLE IV Ingredient: Amount Hydroxyethyl amylose grams 300.0 Unmodified corn starch do 700.0 Pureco Oil ..d-o 410.0

Ethomid HT/lS (ethylene oxide condensate of hydrogenated talloW acid amide-wetting agent) grams 41.0 Cation X do 88.0 Formaldehyde cc 17.0 Water (sufficient to bring to a volume of 5 gallons).

The procedure of Example III was repeated with the exception that the Tween 81 of Example III was replaced with Ethomid HT/ 15 and the unmodified corn starch was cooked in water at 1'60-170 F. for 2 to 5 minutes to partially hydrate the unmodified corn starch prior to adding it to the previously cooked hydroxyethyl amylose solution. With this formulation properties equal to those secured in Example III were obtained, and in ad-.

dition, it was noted that there is an improvement of the shedding properties of the yarn produced according to Example III, there being practically no shedding during fabrication. The abrasion resistance of the glass fibers sized with this aqueous sizing composition was 42 cycles. Practically no migration occurred.

The abrasion resistance values were obtained from a simple testing apparatus and indicate the number of oscillating movement cycles (number of abrading rubs) given to the tensioned yarn prior to breakage. The apparatus involved essentially four winding posts arranged in rectangular fashion with the two upper posts being generally parellel to the bottom posts. A smooth sur faced round post is provided to allow the yarns to be crossed by one another in abrading contact in the same manner as links in a chain. The four outside posts were spaced apart fboth vertically and horizontally. The center smooth surfaced round post is spaced slightly to the left of the vertical center of the rectangle refined by the four outer posts.

A first yarn specimen is clamped to the upper lefthand post, guided around the central round post under slight tension and clamped at the lower lefthand post. The said first specimen is cut to allow about /2 inch yarn to protrude from the said posts. A second yarn specimen is pulled through the loop formed by the first specimen from front to back. One free end of the second yarn specimen is then threaded around the upper righthand post up to and around another post located outside of the said rectangle (above and slightly to the right of the upper righthand post located in the rectangle) and down to the tensioning post (located below the lower righthand post in the said rectangle.) The other (lower) free end of the said second yarn specimen is passed around the lower righthand post in the said rectangle and then passed downwardly and clamped to the said tensioning post.

A weighted tension of 80 grams is then applied to the tensioning post. A horizontally disposed bar is eccentrically secured to the tensioning post on one end and to an oscillating device on the other. The bar is then oscillated causing the second yarn specimen to rub against and therefore abrade the first yarn specimen. The number of oscillations (rubs) were counted. The abrasion resistance of the sized strands is reflected by the number of rubs prior to breakage.

EXAMPLE V Ingredient: Amount Hydroxyethyl amylose grams 1000.0 Corn Products 5341 (40 fluidity sulfuric acid treated corn starch) grams 300.0 Stein Hall ARD-1370 (partially cross- {bonded corn starch wherein the crossbonding agent is phosphorous oxychloride) grams 300.0 Pureco Oil do. 600.0 Tween 81 do 80.0 Carbowax 300 (polyethylene glycol with an approximate molecular weight of 300) grams 3 00.0 Cation X do 176.0 Diglycol stearate do 30.0 Water (Sufiieient to bring to a volume of 10 gallons).

The procedure of Example III was followed with the exceptions that (a) Stein Hall ARD-1370 and Corn Products 5341 were cooked in water (approximately 5 gallons at 212 F. for 30 minutes before adding to the hydroxyethyl amylose solution, which had been cooked previously at a temperature of 180 F. for 15 minutes; and (b) the Pureco Oil was emulsified with diglycol stearate and Tween 81 prior to adding it to the size. This aqueous size composition had a solids content of about 7.3 weight percent. With this formulation the size content of 54,000 yards of glass fiber yarn varied from 1.69 percent on the outside 300 yards of the forming package to 1.40 percent on the inside 300 yards. The average size content was 1.4 percent (ignition loss) after drying and conditioning the sized strands as in Example I. The abrasion resistance of the glass fiber yarn sized with this sizing composition was 43 cycles. This size formulation showed excellent results in Warping trials, viz., 0.13 break/million end yards, and also possessed excellent quilting, weaving, and general forming propersizing materials (for example, warp sizes).

fourth valence bond of the silicone atom is occupied by a primary, secondary amino group, -R NH--R NH where R and R are alkyl groups having 2 to 4 carbon atoms) grams 100.0 Diglycol stearate do 30.0 Water (Sufiicient to bring to a volume of 10 gallons).

The procedure of Example V was followed and the sized yarn possessed essentially the same abrasion resistance (42 cycles) and general forming properties as in Example V. The average size content was 1.4 percent (ignition loss). Practically no migration occurred.

EXAMPLE VII Ingredient: Amount Hydroxyethyl Amylomaize (hydroxyethyl derivative of hybrid corn starch having an amylose content of approximately 55 percent by weight prepared by reacting ethylene oxide, 10 to 20 weight percent, with Amylomaize) grams 1000.0 Corn Products 5341 do 300.0 Stein Hall ARD-1370 do 300.0 Pureco Oil do 600.0 Tween 81 do 80.0 Carbowax 300 do 300.0 Cation X do 176.0 Diglycol sterate do 30.0 Water (Sufficient to bring to a volume of 10 gallons).

The procedure of Example V was repeated with the exception that hydroxyethyl Amylomaize was employed in place of hydroxyethyl amylose, and the sized glass fiber yarn possessed essentially the same abrasion resistance (44 cycles) and general forming properties as in Example V. The average size content was 1.4 percent (ignition loss). Substantially no migration occurred.

EXAMPLE VIII Ingredient: Amount Hydroxyethyl Superlose grams 1000.0 Corn Products 5341 do 300.0 Stein Hall ARD1370 do 300.0

Polyethylene glycol stearate (Water dispersible sterate of polyethylene glycol having a molecular weight of approximately 400) grams 680.0 Cation X do 176.0 Water (Sufiicient to bring to a volume of 10 gallons).

The procedure of Example V was followed with the exception that polyoxyethylene glycol sterate was substituted for Pureco Oil and Tween 81. The abrasion resistance and general forming properties of the sized yarn were the same as those attained in Example V. Essentially no migration occurred.

:13 EXAMPLE IX Ingredient: Amount Hydroxyethyl Superlose grams 1000.0 Epolene (readily emulsifiable low molecular weight linear polyethylene having a molecular weight of 1400 to 2500) grams 600.0 Pureco Oil do 600.0 Tween 81 do 80.0 Carbowax 3-00 do 300.0 Cation X do 176.0 Diglycol stearate do 30.0 vWater (Sufiicientto bring to a volume of gallons).

The procedure of Example V was followed with the exception that the Epolene was substituted for both the Corn Products 5341 and Stein Hall ARD-1370 of Example V. Essentially no migration occurred, and the sized yarn had an abrasion resistance of 42. The general forming characteristics were excellent.

In various trials of the invention, different amounts of the various ingredients were used in the size. In general, Water makes up about 91 to 96 percent by weight of the size. The high amylose containing starch derivative of the aforesaid formula, XOY, generally constitutes about 1.5 to about 4 percent by weight of the size. The lubricant is present in the size in amounts of about 25 to 100 percent by Weight based on the amount of the starch materials, and preferably about 45 percent by weight of the said amylose containing starch derivative.

'Various textile softeners which are equivalent to Cation X can be employed in the size in amounts which are sufficient to provide a softening action to the sized strand, such amounts being, for example, 4 to percent by weight of the said amylose containing starch derivative, and preferably about 10 percent by Weight of the said amylose containing starch derivative. Suitable textile softeners are alkyl imidazoline derivatives such as described in US. Patents Nos. 2,200,815; 2,267,965; 2,- 268,273 and 2,355,837.

Cation X is an example of such a material wherein the alkyl imidazoline derivative is the reaction product of stearic acid, tetraethylene pentamine and acetic acid. Acid solubilized, water-dispersible stearic amides and auhydrous, acid solubilized, water dispersible lower molecular weight fatty acid amides, as well as anhydrous, acidsolubilized, polyunsaturated, lower molecular weight fatty acid amides can also be used as a softener. Some of these softeners also serve .as wetting agents, for example, the alkyl imidazoline derivatives.

Likewise, various wetting agents similar to Tween 81 can be employed in the size in sufficient amounts to permit adequate wetting of the sizing ingredients to the glass surface with suitable amounts of Wetting agent ranging from 8 to 13 weight percent of wetting agent based on the weight of lubricant, and preferably about 10 percent by weight of the lubricant.

Suitable wetting agents include cetyl or stearyl monoarnine hydrochloride or acetate, dodecyl amine, hexadecylamine and secondary and tertiary derivatives of the same, for example, dodecylmethylamine and salts thereof. Quaternary ammonium compounds, such as trimethyl stearyl or cetyl ammonium bromides and chlorides, and generally any of the amine compounds which dissociate in aqueous systems to provide a positive radical containing a group of more than 10, preferably 12 or more carbon atoms can be employed. These materials are cationic active substances.

Non-ionic wetting agents can also be used. They are not as surface active as cationic wetting agents, and therefore are generally used in greater amounts to provide the same degree of wetting. Examples of suitable non-ionic wetting agents include polyalkylene derivatives of esters,

fatty acids, fatty alcohols, fatty amides, alkyl phenyl ethers and other derivatives.

A bactericide, such as formaldehyde, is usually employed in suflicient amount to prevent mold attack on the amylose containing starch derivative. Suitable effective amounts of the bactericide are about 3 milliliters to 1 gallon of the sizing composition.

The overall solids content of the size can vary from about 2.0 to 8.0 percent by weight. Generally the solids content will range from 6.0 to 7.5 percent by weight and preferably from 7.1 to 7.3 percent by weight. By solids content is meant the residual solids remaining after drying the sizing composition at 105 C. to constant weight.

Although the present invention has been described with respect to the specific details of certain embodiments thereof, it is not intended that such details serve as limitations upon the scope and spirit of this invention.

We claim:

1. An aqueous glass fiber sizing composition consisting essentially of in percent by weight, 91 to 96 percent water, 1.5 to 4 percent of an amylose containing starch derivative of the formula, XOY,

wherein X is a high amylose containing starch having an amylose content of from about 50 percent to 100 percent by weight,

0 is an oxygen atom from a hydroxyl group in the amylose portion of the starch molecule, and

Y represents hydroxy lower alkyl radicals, and wherein Y is a substituent on the said amylose with a weight average frequency of occurrence of from about 0.1 to 30.0 Y substituents per 100 d-glucopyranose units of the amylose portion of the said starch,

an effective amount up to about 2 /3 times the weight of the amylose containing starch derivative, XOY, of an additional film forming agent selected from the group consisting of (1) an unmodified starch, (2) a cross-linked starch, (3) an acid treated hydrolyzed starch having a fluidity of about 30 to 50, (4) a readily emulsifiable polymer of an olefin containing 2 to 3 carbon atoms having a molecular weight of 1400 to 2500, and (5) combinations thereof,

25 to 100 percent of a lubricant based on the weight of said amylose containing starch derivative, XOY, and said additional film forming agent, and

4 to 15 percent by weight of a textile softener based on the weight of the said amylose containing starch derivative XOY,

said aqueous sizing composition having a viscosity of about 1 to 100 centipoises at 20 C.

2. The compositions of claim 1 wherein the film forming agent constitutes 0.6 to 2.33 times the weight of said amylose containing starch derivative.

3. The composition of claim 1 where the film forming agent is unmodified corn starch.

4. The composition of claim 1 Where the film forming agents are a partially cross-bonded starch and an acidtreated corn starch having a fluidity of approximately 30 to 50.

5. The composition of claim 1 wherein the film forming agent is a readily emulsifiable low molecular weight polyolefin selected from the group consisting of:

(a) polyethylene,

(b) polypropylene, and

(c) mixtures of (a) and (b).

6. A glass fiber strand whose individual filaments are coated with the dried residue of the sizing composition set forth in claim 1.

7. A glass fiber strand Whose individual filaments are coated with the dried residue of the sizing composition set forth in claim 3.

8. A glass fiber strand whose individual filaments are coated with the dried residue of the sizing composition set forth in claim 4.

9. A glass fiber strand Whose individual filaments are coated with the dried residue of the sizing composition set forth in claim 5.

10. A dried forming package of non-migratory sized glass fiber strand comprising a support for the strand and a dried, sized continuous glass fiber strand wrapped therearound, the filaments of said strand being coated with the dried residue of the sizing composition set forth in claim 1, and said strand being characterized by having a substantially uniform size solid content throughout the extent of the strand on the forming package.

11- In the method of forming glass fiber strands which comprises the steps of:

(a) drawing glass filaments from a molten supply of glass at a high rate of speed,

(b) applying an aqueous sizing composition to the filaments as they are being drawn,

() gathering the filaments and combining them into a strand, (d) winding the sized strand on a rapidly rotating forming tube, and

(e) conditioning the strand Wound on the forming tube to reduce the moisture content of the strand to that amount which is acceptable for twisting the strand 12. The improvement in the method set forth in claim 11 wherein the sizing composition is the composition set forth in claim 3.

13. The improvement in the method set forth in claim 11 wherein the sizing composition is the composition set forth in claim 4.

14. The improvement in the method set forth in claim 11 wherein the sizing composition is the composition set forth in claim 5.

References Cited by the Examiner UNITED STATES PATENTS 2,710,275 6/ 1955 Waggoner.

2,771,659 11/1956 Ball.

2,798,020 7/1957 Balz et a1. 156-167 2,799,598 7/1957 Biefeld et a1 156-167 2,993,872 5/1961 Gagnon et al. 106-211 3,036,935 5/1962 Tolkema.

3,051,700 8/1962 Elizer et al 106-210 3,108,891 10/1963 Chron et a1 106-213 ALEXANDER H. BRODMERKEL, Primary Examiner.

EARL M. BERGERT, Examiner.

D. I. DRUMMOND, D. I. ARNOLD,

Assistant Examiners. 

1. AN AQUEOUS GLASS FIBER SIZING COMPOSITION CONSISTING ESSENTIALLY OF IN PERCENT BY WEIGHT, 91 TO 96 PERCENT WATER, 1.5 TO 4 PERCENT OF AN AMYLOSE CONTAINING STARCH DERIVATIVE OF THE FORMULA, X-O-Y, WHEREIN X IS HIGH AMYLOSE CONTAINING STARCH HAVING AN AMYLOSE CONTENT OF FROM ABOUT 50 PERCENT TO 100 PERCENT BY WEIGHT, O IS AN OXYGEN ATOM FROM HYDROXYL GROUP IN THE AMYLOSE PORTION OF THE STARCH MOLECULE, AND Y REPRESENTS HYDROXY LOWER ALKYL RADICALS, AND WHEREIN Y IS A SUBSTITUENT ON THE SAID AMYLOSE WITH A WEIGHT AVERAGE FREQUENCY OF OCCURRENCE OF FROM ABOUT 0.1 TO 30.0 Y SUBSTITUENTS PER 100 D-GLUCOPYRANOSE UNITS OF THE AMYLOSE PORTION OF THE SAID STARCH. AN EFFECTIVE AMOUNT UP TO ABOUT 21/3 TIMES THE WEIGHT OF THE AMYLOSE CONTAINING STARCH DERIVATIVE, X-O-Y, OF AN ADDITIONAL FILM FORMING AGENT SELECTED FROM THE GROUP CONSISTING OF (1) AN UNMODIFIED HYDROLYZED STARCH HAVING A FLUIDITY OF ABOUT TREATED HYDROLYZED STARCH HAVING A FLUIDITY OF ABOUUT 30 TO 50, (4) A READILY EMULSIFIABLE POLYMER OF AN OLEFIN CONTAINING 2 TO 3 CARBON ATOMS HAVING A MOLECULAR WEIGHT OF 1400 TO 2500, AND (5) COMBINATIONS THEREOF, 